Organophosphate esters in children and adolescents in Liuzhou city, China: concentrations, exposure assessment, and predictors.

Meng Yu,Xiang Li,Youjie Wang,Lulu Song,Yaping Li,Ling Liu,Surong Mei,Bingqing Liu,Limei Wang,Liqin Hu

doi:10.1007/s11356-021-18334-0

Abstract

Dermal contact with dust is commonly considered an important pathway of exposure to organophosphate esters (OPEs), but the importance of OPE uptake from diet is unclear. Herein, we used hand wipes to estimate OPE exposure from indoor dust and examined whether urinary OPE metabolite concentrations were influenced by sociodemographic characteristics, OPE amount in hand wipes, and dietary factors. OPEs were measured in urine and hand wipes from 6 to 18-year-old children and adolescents (n=929) in Liuzhou, China. Sociodemographic and dietary factors were obtained from questionnaire. Six OPE metabolites were detected in >70% of the urine samples, and seven OPEs were detected in >50% of the hand wipes. Estimated daily intakes (EDIs) were calculated using urinary OPE metabolites to investigate the total daily intake of OPEs, in which 0.36-10.1% of the total intake was attributed to the exposure from dermal absorption. In multivariate linear regression models, sex, age, and maternal education were significant predictors of urinary OPE metabolite concentrations. Urinary diphenyl phosphate (DPHP) is positively associated with its parent compounds 2-ethylhexyl-diphenyl phosphate (EHDPP) and triphenyl phosphate (TPHP) in hand wipes. High versus low vegetable intake was associated with a 23.7% higher DPHP (95% confidence interval (CI): 0.51%, 52.1%). Barreled water drinking was associated with a 30.4% (95% CI: 11.8%, 52.0%) increase in bis(1-chloro-2-propyl) 1-hydroxy-2-propyl phosphate (BCIPHIPP) compared to tap water drinking. Our results suggested the widespread exposure to OPEs in children and adolescents. In addition to dermal absorption, dietary intake may be an important exposure source of certain OPEs.

Highlights

Organophosphate esters (OPEs) are increasingly used as flame retardants and plasticizers in consumer and industrial products due to the phase-out of some polybrominated diphenyl ethers (PBDEs)
Human dermal absorption of OPEs could be estimated using the mass of OPEs in hand wipes, which has been reported in biomonitoring studies (Liu et al, 2017; Xu et al, 2016)
A total of 51.9% of mothers attained less than a high school degree, 24.7% attained equal to a high school degree, and 23.4% participated in college

Summary

Introduction

Organophosphate esters (OPEs) are increasingly used as flame retardants and plasticizers in consumer and industrial products due to the phase-out of some polybrominated diphenyl ethers (PBDEs). Because OPEs are frequently physically mixed with polymers, they can released from treated products into the external environment, leading to a frequent detection of OPEs in air (Hou et al, 2021), sediments and waters (Ye et al, 2021), foodstuffs (Li et al, 2019a), and biota (Pantelaki and Voutsa, 2020) Concerns regarding these replacement OPEs have mounted, because toxicological studies suggested that some OPEs are considered endocrine disruptors (Liu et al, 2012), and carcinogenic- (Böckers et al, 2020), neurodevelopment- (Rock et al, 2020), and reproductive toxicants (Xu et al, 2017b). Human dermal absorption of OPEs could be estimated using the mass of OPEs in hand wipes, which has been reported in biomonitoring studies (Liu et al, 2017; Xu et al, 2016)

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